In recent years, signal operation tends to high frequency for high speed transmission and large-capacity information processing with the development of high performance, high function and networking of information communication equipments. Meanwhile, in order to meet the requirement trends of various kinds of electronic products, circuit boards are developed in the direction of high multilayer and high wiring density. This requires that the substrate materials shall have not only better dielectric properties to meet the demands on high frequency transmission of signals, but also better heat resistance and mechanical processability to meet the demands on reliability and processability of multilayer printed circuit boards.
Polyimide is one of the organic polymer materials having the best overall performances and it has high temperature resistance to higher than 400° C. However, it has a low solubility and a hard processability.
Bismaleimide (BMI) is another type of resin system derived from polyimide resin system and is a bifunctional compound using maleimide as active end groups, which overcomes the defect that epoxy resins have a relatively lower heat resistance, but still has problems of low solubility, being easy to phase separation and high curing temperature.
CN101831051 discloses an epoxy resin containing naphthalene ring, dicyclopentadiene ring and imide structures. However, there contains a higher content of naphthalene ring, and pyromellitic dianhydride having a worse solubility, the epoxy resin has a high brittleness, a worse solubility and is easy to having a phase separation, as well as has a high cost.